Portion of a display screen with a graphical user interface



The single view is a front view of a portion of a display screen with a graphical user interface.

The broken lines showing a portion of a display screen form no part of the claimed design. The remaining broken lines showing the graphical user interface form no part of the claimed design. 

CLAIM The ornamental design for a portion of a display screen with a graphical user interface, as shown and described. 